Automatic clutch.



S. SIVHTH.

AUTOMATIC CLUTCH.

APPLICATION HLEDJUNE10.1914.

Patented my 20, 1915.,

2 SHEETS-SHEET l.-

` S. SMITH.

AUTOMATIC CLUTCH.

` APPLICATION FILED JUNE 10, 1914. Llli :if l Patented my 20, T915.

' 2 SHEETS--SHEET 2.

SIDNEY SMITH, 0F DETROIT, MICHIGAN.

Specification of Letters Patent.

AUTOMATIC CLUTCH.

Application led June 10, 1914. Serial N0. 844,117.

To all whom 'it may concern:

Be it known that I, SIDNEY SMITH, subject of Great Britain, residing atDetroit, county of Wayne, State of Michigan, have invented a certain newand useful Improvement in Automatic Clutches, following to be afull,clear, and exact description of the same, such as will enableothers skilled in the art-to which it pertains to make and use th`esame,l reference being had to the accompanyin form a part of this specication.

My invention relates to an automatic positive drive ball clutch, adaptedfor use Wherever itis desired to positively drive a freewheel or a freeshaft in one direction and to automatically free the wheel or shaft fromthe driving member upon the stoppage or the reverse motion of thedrivlng member, the construction being such that the driven wheelorshaft is free to turn in either direction until again engaged by theclutch mechanism actuated by a forward movement of the driving member.

One of the objects ofthis invention is to provide a positive mechanicalmeans for shifting thel balls of the clutch mechanism into either alocked or into a released position as may be required ;-the constructionproviding for the automatic escapement of the balls from their drivingrelation 4when permitting the driven member to run free either forwardor backward as may be desired.

While my invention is well adapted for any lor all of the uses to whicha clutch of this character may be employed, it is especiallyadvantageous for coaster brakes for bicycles, lawn mowers, self startersfor internal combustion engines,-it being essential inthe latter casethat upon the engine operating under its own power at a speed greaterthan the starter, that the clutch mechanism should be instantly andautomatically released from connection with the motor by which theengine was initially turned over.

Other advantages and improvements willV hereafter appear.

In the drawings accompanying this speciication-Figure 1 is alongitudinal sectional view through the clutch member indicating afragmentary portion of the driving shaft and a portion of the frame ofthe machine in which it is journaledz-the drive wheel being free to turnin either direction. Fig.

and declare thel drawings, whichA hereafter referred to as the spoolcam. Fig.

3 is a cross-sectional view through the drive shaft, and the spool camon line 3 3 of Fig. ll showing the balls lodged in their respectivecamgrooves in the hub of the sprocket wheel. Fig. 4 is an elevation of thecam hub of the sprocket wheel. Fig. 5 is a fragmentary plan view of anautomobile chassis and its prime mover, indicating a self startercarrying a sprocket wheel connected by'a dri ving chain with thesprocket wheel on the shaft of the prime mover. Fig. 6 is an enlargedfragmentary detail indicating a driven sprocket wheel keyed to the shaftof the prime mover and directly below it the driving sprocket,-withparts broken away to show the clutch mechanism, mounted on the shaft ofthe self starter. Fig. 7 is a fragmentary detail of a modification, inwhich the driving sprocket is keyed Ito the driving shaft, connected bya chain (not shown) with the sprocket wheel above, the driven sprocketbeing partially broken away and in sectiontaken on line 7-7 of Fig. 9.Fig. 8 is a fragmentary elevation of the shaft shown in Fig. 7 with thespool cam mounted upon the shaft, the spool cam being separated from thecam integral with the shaft in order to more clearly disclose theconstruction of the respective parts. Fig. 9 is a cross sectional viewon line 9 9 of Fig. 7 looking toward the hub of the sprocket. Fig. 10 isan elevation of the hub of the driven sprocket wheel. Fig. 11 is alongitudinal sectional view through the shaft and cam spool in assembledrelation.

.Referring now to the letters of reference placed upon the drawings A,denotes a driving shaft, and as indicated in Fig. 5 of the drawings itmay be the armature shaft of an electric self starter B.

A is a driven shaft and A2 wheel keyed to the shaft A.

As denotes an internal combustion engine.

is a sprocket C, indicates a sprocket wheel having al C2 is a nutengaging the hub C to lock the sprocket wheel upon the hub.

C8 denotes inclined grooves formed in the l raten-ted .my 2o, 1915. o

hub to receive the respective balls D, and a indicates coactinglongitudinal grooves in the shaft A, in which lodged. o

E, is a collar secured to the shaft by a set screw e.

F, denotes a spool cam loosely sleeved upon the shaft having on one sidean annuthe balls' are .partially lar flange F', projecting into the hubof the sprocket Wheel. The iange F is4 provided with a'plurality ofslots indicated at f, forming inclined cam Ways for the balls leadinginto the grooves f in the body of the spool cam F.

F2 is an annularl sp1ing flange projecting from the opposite side of thecam spool into the journal bearing for the shaft A, or other suitablestationary member z-theliange be* ing divided as indicated at f2 tovprovide a yielding edge and thus increase its resiliency.

The spring flange ofthe spool cam provides a slight frictionalresistance to its ro- Wheel to the shaft, whereby the Wheel ro- .lettersits operationvvill nowf be more fully explained.

In Fig. 1 the sprocket Wheel C is free to turn in either direction uponthe driving shaft A,-vvhile Fig. 6 shows the balls of the clutch inposition to lock the sprocket tates With the shaft and by means of asprocket chain c may drive a sprocket'vvheel A2 on the drivenshaft A.The sprocket Wheel C shown in Fig. 1 is free to turn in either directionWhen thedriving pressure is off the driving shaft and synchronous withtire rotation of the driving shaft, the balls, which are partiallylodged Within the 4longitudinal grooves a of the shaft, are forced alongthe longitudinal grooves o f the shaft by the inclined guide Walls ofthe spool cam F, in turn yieldably held against rotation with the driveshaft by its spring flange F2, engaging the journal bearing of theshaft, or'other part adapted to momentarily retard its rotation. Thespool cam F is momentarily held against rotation with the drive shaft A,through the resilient action of its spring 4flange F2, which yieldinglyengages the stationary journal bearing of the driving shaft. It willtherefore be obvious that the balls Will through contact With theinclined Walls of the momentarily held spool cam, be forced therebyalong the grooves in the shaft When the latter'is rotating to the right,orin the direction of the arrow, until they reach the limit of theirtravel, as indicated in Fig. 6, in which position the sprocket Wheel islocked to the drive shaft by the coaction of the balls 1). Upon theballs reaching their limit of travel as indicated in Fig. 6, thesprooketvvheel and spool cam will rotate as a unit with the drivingshaft, so long as the shaft is actuated, but immediately upon thedriving power ceasing to operate the shaft, or upon the speed of thedriven sprocketl Wheel exceeding that of the driving shaftf-as in astarter forinter-nal combustion engines-the sprocket wheel movingforward under its acquired momentum will cause the balls to contact withthe inclined faces c to 0 of the grooves C3 in the hub of the sprocketWheel C, Which serves topush the balls out along the longitudinalgrooves a of the driving shaft, causing the spool cam F at ther sametime to rotate suliiciently to permit the balls to travel the fulllength of the longitudinal grooves back to their initial position asindicated 1n Fig. 1,-Wherein the sprocket Wheel is free to turn ineither direction upon the shaft.

In the modification indicated by Figs. 7

90 drive the shaft 'I-I,

to 11 the sprocket Wheel Gr, (or other driving gear) is designed to theshaft being free to turn in either direc-l tion Within the drivingsprocket Wheel, Vwhen the latter is not rotating.

In the modification the shaft H is larger in diameter, a portion of itslength, the end. of the enlarged portion being cut away to provideinclined grooves h, corresponding With the inclined grooves Ciofthe hubQ previously described. The spool cam I, 1s provided on one side With aplurality of inclined guides I', adapted to register With the groovesIt, the flange portion I2, of guides I overlapping the end of theenlarged portion-fof the shaft H-fsee Fig. 11. The opposite side of `thespool cam carries an annular spring flange I3, adapted to en gage thejournal bearing or other stationary' part to momentarily check itsrotation, the construction and operation being similar to the s ool campreviously described.v The hub of the sprocket Wheel G is provided witha plurality in which the balls D are partially lodged, It Will now beapparent that upon powerv being applied to the sprocket Wheel G, thatthe balls D partially lodged Within the longitudinalgrooves g in the hubGr Will be forced by the inclined guides I of the spool cam I, to theposition indicated in Fig. 7 of the drawing in which the'drivingsprocket is shovvnlocked to the shaft. Coincident with the suspension of the driving operation of the sprocket Wheel G, the inclined facelaf-41.2 of the groove 71. formed in the shaft I-I, will force the ballsback to the opposite end of the longitudinal grooves g in the hub Gr;thereby releasing the shaft from its locked .relation with the drivingsprocket Wheel G-the shaft being now free of longitudinal groovesg l l,scribed, provisions being made in the modiiication, however, for a freeshaft (forward or back) adapted to be driven by the driv l mg sprocketas a single unit therewith upon the application of power to the drivingsprocket, in lieu of the previously described free y sprocket wheel(forward and back) mountedupon the driving shaft.

Having thus described my invention, what I claim is y 1. In a device ofthe character described, a driving member provided with a plurality ofgrooves disposed longitudinally to the axis of thel driving member, aball lodged in each of the several grooves, a driven member journaledconcentric to the driving member provided with a plurality of groovesadapted to receive the respective balls, the wall on one side of eachgroove being at an angle to the opposing wall of the groove, whereby itmay serve as a cam to force the balls out of the grooves of the drivenmember upon the coperating driving member ceasing to operate as adriving member, and means coperating with both the driving and drivenmembers to force the balls along the longitudinal grooves of the drivingmember into the grooves of the driven member that the driving and drivenmembers may rotate as a single unit.

2. In a device of the'character described, a driving member providedwith a plurality of grooves disposed longitudinally to the axis f thedriving member, a ball partially Alodged in each of the several grooves,a

driven member journaled concentric to the driving member provided with aplurality of grooves adapted to receive the respective balls, the wallon one side ofeach groove being on an angle to its opposing wall,whereby said angular 'walls may serve in conjunction with the inclinedgrooves of a spool concentric with the driving member as cams to forcethe respective balls out of the grooves in the driven member that thelatter may be free to turn in either direction upon the driving memberceasing to operate, a spool concentric with the axis of the drivingmember having angularly arranged slots and grooves adapted to'fo'rce therespective balls along the longitudinal grooves of the driving memberinto or out of the grooves of the driven member, whereby the driving anddriven members may be locked together as a unit or released from drivingengagement, and means carried by the spool to retard its rotation,whereby the balls may be forced to the limit of their travel in eitherdirection along the longitudinal grooves of the drivingv member throughthe co-action of the angularly arranged slots and grooves of the spool.

3. In a device of the character described, a driving shaft provided witha plurality of longitudinally disposedA grooves, a ball partially lodgedin each of the several grooves, a gear mounted upon said shaft having ahub provided with a plurality of grooves adapted to receive therespective balls, the wall on one side of each of the latter groovesbeing at an angleto its opposing wall, whereby said angular walls mayserve in conjunction with the inclined grooves of a spool concentricwith the drivballs out of the grooves in the gear upon the shaft ceasingto operate, a spool concen- 4tric with the axis of the driving shafthaving angularly arrangedfslots and grooves adapted to force therespective balls along the longitudinal grooves of the driving shaftinto or out of the grooves of the gear hub,

whereby. the driving shaft and gear may be SIDNEY SMITH.

.Witnesses:

S. M. EBERT, S. E. THOMAS.

so Y

ing shaft as cams 'to force the respective l

